JPH07173533A - Rolling method for fe-cr-co alloy - Google Patents

Abstract

PURPOSE:To suppress the occurrence of cracking at the time of coil rolling, prevent the production of a short sized coil and improve the product yield from the stock by executing warm rolling at an intensive draft after solution treatment. CONSTITUTION:In the case a magnetic alloy having a compsn. contg., by weight, 20 to 40% Cr and 5 to 30% Co, and the balance substantial Fe is formed into a steel material, in general, the method by melting, hot rolling, solution treatment and cold rolling is adopted. Since cracking occurred in the process of cold rolling and by coiling in the process of the cold rolling can not be avoided, it is rapidly cooled down from 1000 to 1300 deg.C, is subjected to solution treatment to form into a alpha single phase and is thereafter subjected to warm rolling of >=30% draft at 100 to 500 deg.C. By this treatment, the occurrence of cracking in the process of the warm rolling and, furthermore, cold rolling in the following stage can be suppressed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to Fe, Cr and Co.
More specifically, the present invention relates to a rolling method capable of suppressing cracking during rolling, preventing shortening of a coil, and reducing working time.

[0002]

2. Description of the Related Art It has long been known that Fe-Cr-Co alloys are spinodal decomposition type permanent magnets, but due to the complexity of heat treatment and the strictness of temperature control, they are difficult to mass produce. There was In recent years, attention has been paid to the fact that it has favorable magnetic characteristics for small relays. The basic components of a general Fe-Cr-Co magnet alloy are Cr: 20 to 40% by weight, Co: 5 to 30% by weight, and the balance is Fe. Among them, those currently industrialized. Is Cr 25 to 35% by weight,
Most of the composition is Co: 10 to 20% by weight and Fe: balance. Furthermore, 0.1 to 5% of Ti, Z
r, Hf, V, Nb, Ta, Mo, W, Mn, Si, A
It is also known that the magnet characteristics are improved by adding 1 or Ni as a residual active ingredient.

Conventionally, Fe-Cr-Co alloys are difficult to cold-roll due to the influence of the precipitation phase, and crack during the rolling.
At present, in order to perform cold rolling easily, at present, a quenching process (solution treatment) is added before the cold rolling process. It may crack during winding during cold rolling. In order to suppress cracks during rolling as much as possible, cold rolling is performed by increasing the rolling rate once, but cracks cannot be suppressed directly, and short coils are produced. It is supposed to be. Therefore, an extra working time is required because the number of times of coil replacement is increased during processing such as pressing. Further, since the coil is short, the yield of the product is low, and the material cost per product unit is considerably high. From these things, improvement of the rolling method was desired.

[0004]

[Problems to be Solved by the Invention] It is possible to suppress the occurrence of cracks in a Fe-Cr-Co alloy, which has been conventionally said to be a material difficult to be rolled, during rolling work, thereby improving the efficiency of cold rolling work, and a short coil. It is an object of the present invention to provide a rolling method that significantly reduces the working time by reducing the occurrence of

[0005]

[Means for Solving the Problems] The phase range in which the Fe-Cr-Co alloy can be rolled includes the α-phase single-phase region or the α + γ-phase region. It is known that if you do, it will break completely. Therefore, it is generally said that quenching from 1000 to 1300 ° C. enables the α phase single phase or the α + γ phase to be rolled, and at present, quenching is performed before cold rolling. However, cracks may occur during cold rolling work. This is because even in the α-phase single-phase region, rolling is possible when the crystal grains are made fine, but cracks easily occur when the crystal grains become coarse. In terms of workability, the γ phase is the best. However, since the γ-phase region is adjacent to the unrollable σ-phase region, it is necessary to adequately control the quenching temperature, and the quenching process must be performed by heating the entire rolling material to a uniform temperature. Is actually difficult. Further, when quenching is performed at a temperature at which the α phase becomes a single phase at a high temperature, the crystal grains become coarse and cracks easily occur.

Then, various experiments were carried out to prevent the occurrence of cracks, and it was found that warm rolling produces desirable results in the α-phase single-phase region. That is, warm rolling in the range of 100 to 500 ° C. was effective for easily performing rolling. At temperatures above 500 ° C., workability is poor and surface oxidation proceeds. Furthermore, it is not preferable because cracks and cracks are suddenly generated. At temperatures below 100 ° C, no effect of preventing cracking was observed. Also,
If the rolling rate of the warm rolling after the solution treatment is performed at 30% or less, cracking may occur in the cold rolling of the next step, which is not preferable.

[0007]

EXAMPLES Four types of F having the typical compositions shown in Table 1
e-Cr-Co alloy with a plate thickness of 5 mm and a plate width of 15 mm
The material just after quenching (solution treatment) from 1000 ° C. was used. 50-600 this material
A method of rolling the plate to a thickness of 2 mm in the temperature range of ° C was adopted. The rolling mill used here is a four-high rolling mill. Also, 1
The rolling rate was set to about 30%, and rolling was performed in 3 passes to 2 mm. A pot-type electric furnace was used as the heating device. The results are shown in Table 2.

[0008]

[Table 1]

[0009]

[Table 2] This test is a test in which the temperature is changed stepwise from 50 to 600 ° C. and the rollability according to each composition is confirmed. Each temperature holding time was 1 hour. 100-500 ℃ for each composition
It was confirmed that rolling within the temperature range of 1 does not cause cracking during rolling.

[0010]

According to the present invention, cracking during rolling can be suppressed and generation of short coils can be suppressed. In addition, since it is possible to suppress the generation of short coils, the yield of products from raw materials is improved, and the number of coil replacements is reduced in processing operations such as press working,
A reduction in working time was confirmed.

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Claims (1)

[Claims] 1. A Cr content of 20 to 40% and a Co content of 5 to 3 by weight.
In a method for producing a plate material by melting, hot rolling, solution treatment, and cold rolling a magnetic alloy in which 0% and the balance substantially consist of Fe, a rolling ratio is 30% or more after the solution treatment, and 100 to 100%. A method for rolling an Fe-Cr-Co alloy, which comprises rolling in a temperature range of 500 ° C.